Bacterial phyla

[68] The CPR is a descriptive term referring to a massive monophyletic radiation of candidate phyla that exists within the Bacterial domain.

[27][71] Microgenomates was originally thought to be a single phylum although evidence suggests it actually encompasses over 11 bacterial phyla,[19][5] including Curtisbacteria, Daviesbacteria, Levybacteria, Gottesmanbacteria, Woesebacteria, Amesbacteria, Shapirobacteria, Roizmanbacteria, Beckwithbacteria, Collierbacteria, Pacebacteria.

[2] In line with this, over 14 phyla have now been described within the Parcubacteria group,[19][5] including Kaiserbacteria, Adlerbacteria, Campbellbacteria, Nomurabacteria, Giovannonibacteria, Wolfebacteria, Jorgensenbacteria, Yanofskybacteria, Azambacteria, Moranbacteria, Uhrbacteria, and Magasanikbacteria.

[27][71] The proposed superphylum, Terrabacteria,[74] includes Actinomycetota, "Cyanobacteria"/"Melainabacteria"-group, Deinococcota, Chloroflexota, Bacillota, and candidate phylum OP10.

In 1987, Carl Woese, regarded as the forerunner of the molecular phylogeny revolution, divided Eubacteria into 11 divisions based on 16S ribosomal RNA (SSU) sequences, listed below.

[89] The lack of easily accessible morphological features, such as those present in animals and plants, hampered early efforts of classification and resulted in erroneous, distorted and confused classification, an example of which, noted Carl Woese, is Pseudomonas whose etymology ironically matched its taxonomy, namely "false unit".

The advent of molecular sequencing technologies has allowed for the recovery of genomes directly from environmental samples (i.e. bypassing culturing), leading to rapid expansion of our knowledge of the diversity of bacterial phyla.

Phylogenetic tree showing the diversity of Bacteria, Archaea, and Eukaryota. [ 1 ] Major lineages are assigned arbitrary colours and named, with well-characterized lineage names, in italics. Lineages lacking an isolated representative are highlighted with non-italicized names and red dots.
Atomic structure of the 30S ribosomal Subunit from Thermus thermophilus of which 16S makes up a part. Proteins are shown in blue and the single RNA strand in tan. [ 76 ]